The invention is related to the field of sensors, and in particular to tactile sensors.
A variety of 2-D tactile sensors have been described in the art. In a typical sensor, an array of individual elements change some electrical property, such as resistance or capacitance, in response to pressure. The electrical changes are sensed and conveyed via wires or other electronic means to the controller or user. Another type of tactile sensor is optical. Some optical property such as luminance or reflectance changes as a result of pressure, and a light sensing system detects and conveys the signal to the controller or user.
For an application such as a robot fingerpad, there are a number of properties that are desired in a tactile sensor. It should have high resolution (be able to make fine spatial discriminations), have high sensitivity (be able to detect small variations in pressure), and be compliant (able to elastically deform in response to pressure). The tactile sensor should be manufacturable with reasonably large areas. It should be easily manufactured using inexpensive materials. It has been impossible to achieve all of these goals in a single sensor.